In its first opportunity to shape the future of Halo, new franchise custodian 343 Industries has already made its mark with one bold new directive in particular.

"From a fiction and story standpoint, everything matters," begins executive producer Kiki Wolfkill.

Starting with Halo 4, "everything" includes the multiplayer component. No longer will online Halo battles take place in a vacuum, seemingly disparate from that of the campaign; a world where there's no explanation as to why other Spartans even exist, let alone slaughter each other in combat.

"The story starts in campaign. When the campaign is done, the story actually continues in the Infinity Multiplayer experience," states Wolfkill. "And that's sort of a key thread – having that narrative weave through all parts of the game experience."

In Halo 4's Infinity Multiplayer suite, the player assumes the role of a Spartan enlisted aboard the UNSC Infinity warship, the pride of the UNSC fleet. In the Halo 4 campaign gameplay showcased at E3, we see the UNSC Infinity drawn into the Forerunner shield world Requiem. It's a fate shared not long beforehand by Master Chief and Cortana while both were stranded aboard the damaged UNSC frigate Forward Unto Dawn.

Infinity Multiplayer is split into two parts. The first of these is 'War Games', which represents the traditional Halo multiplayer experience. Here it's explained as a simulated adversarial training exercise for Spartans aboard the Infinity in preparation for field combat.

The second part of Infinity Multiplayer is Spartan Ops, where the Infinity's Spartans are actually deployed into the field. The episodes, consisting of five missions each, will be delivered weekly via Xbox Live. According to 343 Industries, this will continue for "months" after Halo 4 sees its retail release.

But the best part of Spartan Ops is that these missions are not delivered without context, and in keeping with 343 Industries' new vision, they will drive the Halo story forward. "Each week, there's a new episode of a CG series that's set aboard the UNSC Infinity that follows a group of Spartans called Majestic Team, and it sort of gives you a look into what life is like aboard the ship," explains franchise creative director Josh Holmes.

Each mission will feature CG cinematics of the same standard as those to feature in the campaign. The missions will also play out much like those of the campaign, complete with dialogue and an unfolding plot. Also, Spartan Ops missions will often take place in areas that players haven't already visited in the single player campaign. Essentially, 343 Industries is giving players an additional, episodically delivered campaign, free of charge.

We're told by Wolfkill and Holmes that each mission, on average, takes between 10 to 15 minutes to complete, although this will vary depending on variables such as the player's chosen difficulty (which, as in Halo: Reach, can be set individually for multiple players). Multiply that average by five missions, and that's around an hour of extra campaign content per week, additional cinematics not included.

While Master Chief won't be at the centre of this particular story, players will develop their own Spartan character with a persistent progression system in both adversarial multiplayer and Spartan Ops.

"We have a very deep and robust progression system, as well as the ability to customise all aspects of your Spartan within the loadout system," continues Holmes.

Our 343 Industries demonstrators talked us through some aspects of the new system as they prepared for a two-player co-operative playthrough of one Spartan Ops mission. According to Holmes, selecting an appropriate loadout may be even more important in Spartan Ops than in the War Games adversarial mode.

"Each of the decisions that you make have a really deep impact within the mission, and depending on what the mission is, you're gonna make different choices," he explains.

This demonstration also served as a first explanation of two new loadout features for the wider Halo 4 Infinity Multiplayer. Not only do players select an armour ability as per Halo: Reach, but they're now offered a selection of tactical and support packages. Holmes didn't exhaustively explain each of them, but his choices for this demonstration provided a glimpse of insight.

"For my tactical package, I'm going to pick firepower. Firepower allows me to carry two primary weapons into the battlefield, and so this is going to allow me to equip two rifles. I'm going to select the DMR and then have the BR as my secondary weapon," says Holmes.

"And for a support upgrade, I'm going to stick with ammo. Ammo just gives me a little bit of extra ammunition, which is going to be useful in the mission ahead."

The mission itself sees the Spartans of Majestic Team hunt out a Forerunner artifact that has drawn the interest of Covenant troops in the vicinity. It's not explained to us exactly why Elites, Jackals and Grunts are all fighting alongside each other once again, but it's implied that all will become clear during the single-player campaign. Partway through the mission, the Spartans also encounter the new Promethean enemy types introduced in Microsoft's E3 press event. They're quite unlike anything encountered previously, and the Promethean Knight reportedly presents more of a challenge than that Halo staple, the Elite.

Halo certainly has its detractors, but it's hard to deny the appeal of an initiative such as Spartan Ops. It looks set to present an intriguing, ongoing engagement with the story of the Halo universe and a considerable value-add to an already comprehensive package.